Wayne Huntsman was booked Wednesday on suspicion of arson and was being held in lieu of $10-million bail, according to the El Dorado County Sheriff's Office.
He was arrested in Placerville after investigators interviewed numerous people and developed multiple leads, El Dorado County Dist. Atty. Vern Pierson told reporters at a midday news conference.
Officials would not say how they believe the fire was started, citing the ongoing investigation.
The King fire, burning out of control in the Eldorado National Forest east of Sacramento, threatens more than 2,000 homes after ballooning overnight from 27,930 acres to nearly 71,000 acres. Another 1,500 buildings are threatened by the blaze, which was just 5% contained Thursday morning, according to the California Department of Forestry and Fire Protection.
While no injuries or major damage had been reported as a result of the fire, that could change, Pierson said.
"A wild land fire like this is a very dangerous thing," he said.
More than 3,300 firefighters were battling the blaze, which officials said was now costing $5 million a day to fight.
Laurence Crabtree of the U.S. Forest Service said there was no estimate for when the fire might be contained.
The fire prompted Gov. Jerry Brown on Wednesday to declare a state of emergency for El Dorado County. The
The most destructive in terms of damage to property has been the Boles fire, which erupted late Monday and quickly tore through the logging town of Weed, just west of Mt. Shasta. The fire damaged or destroyed more than 150 structures, including churches, a library and the town's sawmill, leading Brown to also declare a state of emergency in Siskiyou County.